Polarized relay with a slug armature forming a bridging contact



Jan. 30, 1968 w. GROBE POLARIZED RELAY WITH A SLUG ARMATURE FORMING A BRIDGING CONTACT Filed May 12, 1966 Unite States atent 3,366,9ii2 POLARIZED RELAY WITH A SLUG ARMAT FQRMING A BRIDGING CGNTACT Wolfgang Grebe, Ludwigsbnrg, Germany, assignor to International Standard Electric Corporation, New York, N.Y., a corporation of Delaware Filed May 12, 1966, Ser. No. 549,577 Claims priority, application Germany, May 26, 1965, St 18,704 4 Claims. (Cl. 335153) ABSTRACT (IF THE DISCLGSURE A relay is provided with an armature suspended within the magnetic field of an annular permanent magnet. Suspension is provided by springs aligned along the axes of both the armature and the annular permanent magnet. The armature is deflected, by the action of electromagnets, from the magnetic field of the permanent magnet Deflec tion occurs along the axis of the armature in opposition to forces provided by the springs as well in opposition to forces caused by the magnetic field of the permanent magnet. Contacts of the relay are located near the ends of the armature and are closed by the armature when it is deflected.

This invention relates to a polarized relay having a reed contact and at least one permanent magnet supported freely in an air gap within an electro-magnet.

Electromagnetic relays with an armature, borne freely in an operating air gap of the relay are known in the prior art. The armatures in such cases are often ball-shaped and operate under the influence of at least one permanent magnet. The permanent magnet may be inserted into a reed tube on one longitudinal side at the level of the contact air gap in this type of construction. This construction is not only difiicult to manufacture, but it does not permit the use of the complete surface of the armature for contact-making.

Other prior art includes arrangements of contacts in a reed tube having a cylindrical armature fixed to a spring. The spring-type fixing of armatures in such contacts has the disadvantage that within the reed tube a third melting-in point occurs, being not within the front and rear small sides of the reed tube. In this construction of a reed contact the armature consists, either entirely or partly, of permanent magnetic material.

The present invention employs another type of reed contact, avoiding the disadvantages of the known constructions. The present construction is simple and permits use of the relay as a switch-over contact, or as a make or break contact. This is achieved, according to a preferred embodiment of the invention by using a cylindrical part as the armature, fastened to a spring to keep the armature in a non-operative position between the ends of the contacting elements. The contacting elements are extended through the ends of a reed tube. The armature is supported within a central space in a ring-shaped permanent magnet and is linked magnetically with one or more electromagnetic coils.

According to an embodiment of the invention the resilient part, holding the armature, protrudes through the reed tube beside the contact elements, either at one or at both ends, is electrically insulated from the contact elements and simultaneously serves as an electric connection to the armature.

According to a further embodiment of the invention the permanent magnet surrounding the reed contact or contacts is ring-shaped and is magnetized radially.

According to a further embodiment of the invention 3,3663% Patented Jan. 30, 1968 the armature consists of a magnetic material which can be changed in its magnetic condition through heavy current pulses of an external magnetizing coil.

According to a further embodiment of the invention the spring is melted into the tube so that it extends through the tube at only one end.

The invention shows, compared with known arrangements of reed switch-over contacts, the advantages that it can be manufactured easily, that due to fixing the armature at the spring a contact transition resistance appears only at one contacting point, and that the armature can be magnetically coupled in a proper way without the necessity that its pole-piece must be enclosed in the reed tube.

The invention is described with the aid of the drawings, wherein:

FIG. 1 shows a relay with a switch-over contact, seen in cross-section and on an enlarged scale,

FIG. 2 shows another example of a relay with one switch-over contact, seen in cross-section and in an enlarged scale,

FIG. 3 shows a relay with one switch-over contact, as shown in FIG. 1 or FIG. 2, in a perspective view.

In FIG. 1 and the other figures, 1 indicates a reed tube at the ends of which contacting elements 2 and 3 and the ends 4 and 5 of two helical springs 6 and 7 are melted into the tube. The ends of the helical springs 6 and 7, located within the reed tube are firmly connected with a cylindrical armature 8, for example by welding at the spots 12 and 13. The helical turns of the springs 6 and 7 are arranged within the reed tube 1 in such a way that I they do not directly touch the contact making elements 2 and 3 within said reed tube. The armature 8 may consist either of a material that can be magnetically influenced or of a soft-magnetic material. In the reed tubes 1 or between them a ring-shaped permanent magnet 11 is arranged, magnetized in the radial direction to cause the armature 8 to assume the magnetic state of a south pole in the configuration shown. Beside the permanent magnet 11, coils 15 and 16 are provided which can be made without a coil body, their individual windings being switched differently, depending on the respective purpose. The armature 8 is supported by the springs 6 and 7 so that it can be moved to the right or left in FIG. 1 in response to magnetic forces from coil 15 and/or coil 16. Motion of the armature 8 serves to close contacts between terminals 3 and 5 or between terminals 2 and 4. Since the 'FIGS. 1 and 2 show only the principle of the invention, the winding ends 17 and 18 of the coil 15 and the winding ends 19 and 20 of the coil 16 are represented, but it is not shown how they are kept mechanically within the relay and electrically insulated from each other. The coils 15 and 16 may be separately wound and may be energized independently through their respective winding ends 17, 18 and 19, 20. These winding ends can be arranged as part of the plug-in construction of a relay in a variety of ways known to the art. For example, the ends of the contact spring 5 and the contact element 3 may be brought out of a cover 21 at the same end as winding ends 17, 18 or 19, 20 or at the same end as the contact element 2 and the contact spring 4. This construction would be suitable for a vertical plug-in type arrangement of the relay. If the relay is to be arranged in a horizontal position, e.g. on a plate or within a rack, the various terminals of the relay can be divided between opposite ends of the cover 21 as shown in the figures and can be further connected to external plugs in known ways.

FIG. 2 shows another example according to the innovation in which within the reed tube 1 a barrel-shaped armature 9 is connected electrically and mechanically with a spring 10 at thepoint 14, e.g. by welding, the ends 4 and 5 of said spring being melted into the tube 1 on both ends in parallel to the contact elements 2 and 3. The armature 9 may consist either of a material that can be influenced magnetically or of a soft-magnetic material. The relays according to FIGS. 1 and 2 may be provided with a cover 21 of a material that can be influenced magnetically, either for shielding or for an improved formation of the magnetic back-flow. Said cover may consist of two semi-circular troughs bent in the vicinity of the terminals of the reed contact 1 towards said terminals, but electrically insulated from said terminals. The spring 10 carries current to the armature 9 and provides the means for resetting said armature into its non-operative position. An increase in the distance between the permanent magnet and the armature compared with the relays known and with regard to the coupling of the magnetic flux is balanced by the possibility to use the entire circumference of said armature. A larger ring-shaped magnet may also enclose several reed-contacts. The armatures themselves can be permanently magnetized, either radially or axially.

FIG. 3 shows an example of a relay according to the innovation with a reed contact, described in FIG. 1 or 2 in a perspective view. The shielding metal sheet 21 has been left OH in this perspective representation for distinct= ness sake.

While the principles of the invention have been described above in connection with specific apparatus and applications, it is to be understood that this description is made only by way of example and not as a limitation on the scope of the invention.

What is claimed is:

1. A polarized relay employing a reed and a movable armature as contact making elements, said relay comprising:

a reed tube of generally cylindrical form sealed at both ends to have end walls,

a reed extending through an end wall of the reed tube to provide means for making'contact outside and insidi the tube,

a cylindrical armature having ends with substantially flat face portions,

a pair of springs fastened to the ends of said cylindrical 10 a ring-shaped permanent magnet positioned around the central position of said cylindrical armature to magnetize said armature thus making it more responsive to the urging of the electromagnetic coil.

2. A polarized relay substantially as claimed in claim 1,

in which said pair of springs is replaced by a single resilient member passing through the armature and sealed through the end walls of the reed tube. 3. A polarized relay substantially as claimed in claim 1, in which the permanent magnet positioned around the central position of said cylindrical armature is magnetized radially. 4. A polarized relay substantially as claimed in claim 1, in which the cylindrical armature is composed of magnetic material of a character which can be changed in its magnetized condition through electromagnetic fields engendered by current pulses in the electromagnet coil.

BERNARD A. GILHEANY, Primary Examiner.

R. N. ENVALL, Assistant Examiner. 

